Eductor type proportioner



May 20, 1969 a. 1.. SHELDALL EDUCTOR TYPE PROPORTIONER Filed Oct. 24, 1965 Sheet of 2 Gmumvo L. SHELDRLL y 1969 e. L. SHELDALL 3,445,067

EDUCTOR TYPE PROPORTIONER Filed Oct. 24, 1965 H I Q8 :32 33 29 25 37 INVENTOR.

GpRLAWD 1,. sHELDfll-L.

'5 v BY 711m United States Patent 3,445,067 EDUCTOR TYPE PROPORTIONER Garland L. Sheldall, 9063 Nagle Ave., Panorama City, Calif. 91402 Filed Oct. 24, 1965, Ser. No. 504,581 Int. Cl. B051) 7/30; F04f 5/48; F16k 19/00 US. Cl. 239318 9 Claims This invention relates to eductor type proportioners and more particularly to a novel eductor including control means for selectively effecting a merger of a secondary fluid with a main carrier stream of another fluid so that the secondary fluid precisely drawn and metered into the carrier stream of the carrier fluid will be substantially constant despite variations of pressure of the entering carrier stream.

In the past, conventional guns or spray devices have been provided for mixing together water with a detergent solution and thereafter aerating it and projecting it as a foaming stream. Such previous devices have been found to be particularly adaptable for washing transportation equipment, and so forth, and when equipped with a brush, has been found to be a highly effective dlshwasher. Such eduotor type proportioner apparatus processes a carrier liquid under pressure through a restrictive throat which opens into an expansion chamber usually disposed coaxially with the throat. A duct for drawing in a secondary liquid enters the eductor from the side so that suction created in the expansion chamber forces the secondary liquid to enter the main carrier stream where it is commingled. Certain types of eductors as described in US. Patent 2,381,589 and 2,571,891, may be balanced, i.e., so constructed that the ratio of fluid volume entering through the duct to the liquid volume entering through the throat remains substantially constant even though the pressure of the liquid entering the throat is varied over a substantial range. Such eductors, while satisfactory in operation, are diflicult to manufacture because of the precision required in control of the several dimensions.

Furthermore, when the eductor is equipped with a dispensing nozzle, it has been found that a substantial back pressure develops in the main carrier stream which has a tendency to push the carrier stream liquid back into the secondary fluid duct when the dispensing nozzle is turned or oriented at an angle to the longitudinal axis of the main carrier stream. Another problem resides in the fact that the low pressure or suction is developed by the main carrier stream in the expansion chamber which creates abnormal stress and strain of the material from which the eductor is constructed as well as on the various operating parts and elements thereof. Substantial distortion of the material then ensues which generally results in cracking and dimensional changes of critical fluid passages.

Accordingly, the difliculties and problems encountered with conventional eductors, either of the balanced or unbalanced type, are obviated by means of the present invention which provides an eductor having a cylindrical throat which opens abruptly into a coaxial cylindrical expansion chamber of larger cross-section, with a suction conduit or secondary duct entering the expansion chamher from the side adjacent the junction of the throat and chamber. A choke in the form of a screen, perfcr rated disc or the like, carried by a discharge nozzle which offers appropriate resistance to the discharging stream, is provided on the outlet of the eductor and a bell-shaped chamber or funnel-shaped duct is formed between the choke and the expansion chamber which prevents a back pressure from forcing the main stream fluid into the secondary duct as the nozzle is manipulated into various positions. In order to handle the low pressure or suction developed in the expansion chamber, I have found that by properly seating a control valve incorporating a fluid passage and a slot into the secondary duct, the vacuum developed in the expansion chamber may be bled to atmosphere via the slot rather than attempting to stop and hold the vacuum at the control valve and when desired, the vacuum can be maintained to draw a second fluid into the main fluid stream via the passage. Means are provided in connection with the slotted valve to vent the low pressure or suction to atmosphere to interrupt the introduction of the second fluid to the main fluid stream. Although a small :restrictor or apertured choke is included in the secondary conduit for passing the second liquid to the expansion chamber, it has been found advantageous to .prevent atmospheric pressure from getting into the secondary liquid container by providing venting means to the container which extends to the bottom of the container and so that atmospheric pressure is introduced to the container only as the liquid held thereby is removed.

The restrictor or choke disposed in the secondary conduit may be employed to establish the proportion of mixture of the second fluid with the fluid of the main stream without disturbing the balance of the eductor. The second choke conveniently takes the form of a bushing which is press fitted into the secondary conduit. The bushing is slidably disposed in the secondary conduit and the conduit includes a seat formed in the wall thereof adjacent the outlet of the secondary conduit into the expansion chamber against which the restrictor is sealed so that the restrictor cannot be drawn or forced into the expansion chamber and so that the pressure from the expansion chamber cannot pass around the second choke.

Therefore, it is a primary object of the present invention to provide a novel eductor having an expansion chamber for creating a suction or low pressure area suflicient to draw a liquid, such as a soap solution, for example, from a container past a metering jet which incorporates a control valve for effecting an eductor discharge which is soft and sudsy in one condition of operation and results in an eductor discharge of clear rinse water in a second condition.

Another object of the present invention is to provide a novel spray head eductor for mixing or merging a second fluid with the fluid of a fast moving main stream which incorporates a bell or funnel type ducting between the expansion chamber and the spray nozzle which prevents a back pressure from developing which would normally force the fluid of the main stream rearwardly into the container for holding the second fluid.

Another object of the present invention is to provide a novel eductor, either of the balance or unbalanced type, which includes a control valve for effecting the merger of two fluids in an expansion chamber and which is provided with adjustable means for selectively venting vacuum which may develop in such a chamber to atmosphere when the control valve is actuated between a fluid mix and a fluid non-mix condition.

Still another object of the present invention is to provide a novel shower spray eductor for merging a liquid held in a container with the main stream of another fluid which precisely meters fluid from the container into merging contact with the main stream by providing a venting means to atmosphere which is disposed in the bottom of the container for holding the second fluid.

Still another object of the present invention is to provide a novel shower spray head having the ability to mix or merge a supply of liquid soap with the main stream of water which incorporates a control valve for selectively communicating the liquid soap with the main stream of water which incorporates a control valve for selectively communicating the liquid soap with the main stream in such a fashion that the shower head is free from limedeposits and clogged ducting or passageways.

Yet another object of the present invention is to provide a novel shower spray apparatus of the eductor type for merging liquid soap with the main stream of water whereby the adverse effects of back pressure encountered in the expansion chamber of the eductor is greatly reduced and which incorporates venting means included in the body of the eductor as well as the control valve for venting undesirable vacuum to atmosphere which is created in the eductor when the control valve is actuated to interrupt the merger of the liquids.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which:

FIGURE 1 is a side elevational view of an eductor of the present invention suitable for use in connection with a shower spray head in which selective mixing of a second fluid, such as liquid soap solution, for example, with a main carrier stream is effected by a control valve;

FIGURE 2 is a perspective view, partly broken away, of the eductor illustrated in FIGURE 1 showing the ducting for the main carrier stream and the ducting for the secondary fluid;

FIGURE 3 is a perspective view of a portion of the eductor incorporated into the apparatus of FIGURE 2;

FIGURE 4 is an enlarged longitudinal sectional view of the eductor illustrated in FIGURE 1 including the disposition of a vacuum breaker in the central duct for the main carrier stream;

FIGURE 5 is a cross-sectional view of the eductor shown in FIGURE 4 as taken in the direction of arrows 5-5 illustrating the control valve in position to elfect merger of the secondary fluid with the main carrier stream;

FIGURE 6 is a cross-sectional view of the eductor shown in FIGURE 4 as taken in the direction of arrows 66 illustrating the ducting to atmosphere for venting the vacuum breaker; and

FIGURE 7 is an enlarged elevational view of a vented closure means for exhausting air to atmosphere in the eductor ducting when the control valve is in position to interrupt the merger of the secondary fluid with the main carrier stream.

Referring now to FIGURE 1 of the drawings, the eductor of the present invention is indicated in the general direction of arrow 10 which includes a body 11 having a main stream inlet tube 12 secured in one end of the body for introducing a first fluid, such as water, under pressure to the eductor. The opposite end of body 11 is provided with an outlet 13 to which may be suitably attached a spray nozzle 14 as indicated in full lines.

Located on the underside of the body 11, there is provided an inlet tube 15 employed for supporting a container 16 which encloses a suitable amount of a second fluid, such as liquid soap, which is intended to be merged with the first fluid in the main stream carrier. The container 16 is detachably coupled to the tube 15 so that the container may be readily replaced after the liquid soap has been dispensed through the eductor 10.

It is to be particularly noted that a control means 17 is provided which extends through the tube 15 that is employed to control the dispensing of the liquid soap in combination with the main carrier stream of water. As shown, the valve means is located in its on position so that the liquid soap is metered to the main stream for commingling therewith which results in the issuing of the commingled main stream via the nozzle 14 in a soft and sudsy discharge. When the control means 17 has been manually actuated to its off position against a stop 20, the application or introduction of the liquid soap to the main water stream is interrupted and prevented. A control handle 21 carried on the control means 17 is arranged to rotate within a body recess 19 between the on and off positions against the limit stop 20 for the off position and against a shoulder 22 formed on the body 11 at one end of the body recess 19 in which the handle 21 travels.

Referring now to FIGURE 2, the eductor illustrated comprises the body 11 having a cylindrical mounting section 25 for receiving the tube 12 for introducing the main fluid stream under pressure to the eductor. As shown more clearly in FIGURE 4, the tube 12 is retained by a key 29 which is force fitted into the body. The tube 12 includes a tapered bore 26 which terminates in an outwardly flared conical bore 27 which is joined to a coaxial cylindrical chamber 28 which is of a greatly larger diameter than the inlet 26. It has been found that the tapered section ahead of the chamber 28 is desirable in that it tends to assure more accurate balancing of the eductor over a wider pressure range by reducing turbulence. Chamber 28 is occupied by a conventional vacuum breaker such as is disclosed in US. Patent 2,646,063 and which includes a deformable elastomeric diaphragm 30 disposed in place against a shoulder 31 by means of a screen 32 pressed about its outer edge marginal region by a plastic-like gasket 33 which is forced against the vacuum breaker by the extreme end of the tube 12 when the tube has been run into the chamber 28 by means of a threadable connection therewith. On the side of the diaphragm 30 opposite to its side facing screen 32, there is in position a coaxially tapered or frusto-conical screen 34 which is mounted on an annular lip portion 35 projecting into the chamber 28. The vacuum breaker is vented to atmosphere via a pair of passages 36 and 37, as seen more clearly in FIGURE 6, which communicate chamber 38 exteriorly of the opposite sides of the body 11 to atmosphere.

The diaphragm is provided with an opening on its central axis 38 so that a stream of fluid under high pressure may be introduced into a coaxial cylindrical throat section 40 of smaller diameter than the bore 26 of the inlet. The throat opens abruptly into a first expansion chamber 41, which is cylindrical in shape and with its rear wall adjacent the throat perpendicular to the axis of the throat and expansion chamber. The first expansion chamber in turn opens into a second coaxial cylindrical restriction chamber 42 of smaller bore, and this in turn opens into a bell or funnel shaped chamber 43. The bell shaped chamber 43 is partially formed in the fitting 13 which is adapted to threadably receive the nozzle section 14, the discharge end of which is closed by choke such as is represented by a perforated plate 46 having a plurality of fluid passages or holes 47, as illustrated in FIG- URE 1. The plate acts as a choke for the main fluid carrier stream.

The eductor as illustrated in FIGURES 24 includes a secondary conduit 50 which extends at right angles to the first expansion chamber and enters it immediately adjacent its rear wall at the point where throat 40 meets with the rear wall of the expansion chamber. This secondary duct, through which a second liquid, such as may be represented by liquid soap, is sucked or drawn into the carrier stream, has a bushing or restrictor choke 51 employed to further increase the proportion of carrier stream to secondary duct stream while maintaining undisturbed the balance obtained by choking the discharge of the eductor with the plate 46. Preferably, the restrictor 51 is a press-fit bushing having a small control orifice, the size of which is determined by the degree to which the proportion of carrier stream to secondary duct stream is to be inceased, i.e., the smaller the orifice, the greater the proportion. By sliding the bushing along the secondary duct, a position of balance may be obtained in each case.

To prevent the restrictor 51 from advancing into the expansion chamber 41 or too far forward in the secondary duct 50, an annular stop 52 is provided against which the tapered end of the restrictor seats so as to prevent further sliding or rectilinear movement of the restrictor upward in the secondary duct 50. Proper seating of the restrictor against the stop prevents the flow of air therebetween which would otherwise have damaging effects.

The tube 15 formed on the underside of the body 11 includes an integrally formed threaded bottle cap 53 adapted to screw on the container 16 holding concentrated liquid soap solution or the like into which a portion of the second duct 50 projects. It is to be noted that the duct 50 continues into the container via a pipe 54 which projects into the bottle or container. A plastic hose 55 is secured to the end of the pipe by means of expansion of the tube about a thickened portion 56 of the pipe wherein the remainder of the tube drops down to the bottom of the container into contact with the liquid soap solution (not shown).

In order to more precisely control the metering of the second fluid through the restrictor 51, the interior of the container is vented to atmosphere via a flexible tube 57 which is suitably fastened to the body 11 so as to communicate with a passage 58 connected to a lightening chamber 60 which is coupled to atmosphere via a passageway 61. A feature of the present invention resides in the fact that the interior of the container is vented from the bottom thereof and not from the top as is the conventional practice. The end of hose 57 is maintained in close proximity to the bottom of the container as is illustrated more clearly in FIGURE 1. For convenience, a bracket member 62 is provided which couples the extreme ends of the tube 57 and hose 55 together in fixed spaced relationship so that the tube and hose become a unit which adds to the convenience and practicality when removing or attaching containers to the threaded connection formed in cap portion 53 of the tube 15. Atmospheric pressure is brought into the container only as quantities of the liquid soap are drawn therefrom via the secondary duct 50 and the drawing power or the suction developed in the expansion chamber does not have the assistance of atmospheric pressure on the top of the fluid pushing the fluid up through the hose and through duct 50 into the expansion chamber. In other words, the liquid held by the container actually has to be drawn from the container by the suction or pressure developed in the expansion chamber 41. This feature has proven to be quite desirable from an economy point of view since the liquid held by the container is normally relatively expensive and is generally in concentrated form as compared to the primary carrier stream fluid.

In the eductor illustrated in the drawings in accordance with the present invention, a control means 17 is provided for selectively introducing or applying the second liquid held by the container to the main carrier stream at the expansion chamber. FIGURES 4 and 5 more clearly illustrate the operation and details of the control means which include a tapered valve stem 70 which is suitably seated in a tapered bore formed in the body 11 so as to intersect and sealingly separate portions of the secondary duct 50. The end of the valve stem 70 terminates in a threaded portion 71 which projects into a cavity 72 into threadable contact with a securing nut 73 which tightens against a washer 74. The washer 74 includes an annular peripheral shoulder which is received over a mating annular shoulder portion of the body 11 indicated by numeral 75 so that the nut, washer and control valve stem are coaxially disposed with respect to each other.

For purposes of venting the expansion chamber when the control means is in its oil position, a slot 76 is provided extending along the longitudinal axis of the stem 70 which communicates between the duct 50 and atmospheric passageway 77 to the washer 74. The washer 74 is intentionally dimensioned undersize with respect to the diameter of the cavity 72 so that air may pass about the washer 74 and be vented to atmosphere via a plurality of apertures, such as aperture 78 formed in an end cap 80 closing the cavity 72. This venting arrangement is large enough to cut off the suction from the duct 50 entirely when the slot 76 is in communication therewith and connected to atmosphere and thus a ready control means is furnished. Conventional eductors normally provide merely a vent directly to the expansion chamber which is closed with the thumb or finger so that a proper pro portion of liquid is drawn through the secondary duct. When the thumb or finger is removed and the vent is open, only the carrier stream is projected from the discharge end of the eductor. Therefore, a substantial improvement in the state of the art is eflected by the present invention which provides a control means which may be manually actuated to either a vented or unvented condition so as to provide the discharge of the carrier stream commingled with the second fluid. In applications where the eductor is incorporated as a shower head, it would be highly undesirable to require the bather to control the shower spray discharge by placing a thumb or linger over a vent hole to determine whether or not the discharge would be sudsy water or clear rinse water.

As illustrated in FIGURES 5 and 6, the control valve is shown positioned in its on condition which places a passageway 81 formed in the valve stem 70 in coaxial alignment with the secondary duct 50 so as to permit the passage of the fluid held by the container therethrough into the expansion chamber 41. It is to be particularly noted, as shown in FIGURE 6, that the slot 76 and passageway 81 are strategically located on the valve stem so that less than 90 rotation of the control means 17 affects communication of either the passageway or the slot with the duct 50 and so that when neither is so communncated, the slot or passageway is sealed and rendered ineffective. The control means 17 operates as an integral part of the venting system so that the vacuum developed in the expansion chamber by the extremely high speed passage of the primary stream carrier therethrough is not merely blocked or held in the secondary duct 50.

Preferably, the nozzle body 11 is suitable for manufacture by such means as injection molding from conventional materials such as plastic or the like. Such a manufacturing process permits the body to be manufactured in primarily two parts such as is indicated by arrows 85 and 86 in FIGURE 2. This also permits for proper indexing of the parts by incorporating tongue and groove arrangements throughout the abutting faces of the parts 85 and 86 such as may be represented by the groove 87 incorporated on the portion of tube 15 of part 85 which mate with projecting tongue 88 integrally formed on the other portion of tube 15 carried on the part 86, as shown in FIGURE 3. Furthermore, inasmuch as the nozzle may be subjected to various temperature differentials ranging from very hot water to very cold water, and inasmuch as the maintenance of various pressure ratios are critical between the various chambers, ducts and passageways in the eductor body, it is extremely advantageous to provide means for maintaining constant wall thickness and clearances so that distortion of passageways and chambers will not occur under various operating conditions and so that damage or breakage such as by cracking will be prevented. It is to be particularly noted that the wall thicknesses and overall distribution of body mass takes into account various functions of material expansion and contraction. For example, elongated slots, such as interior slot 90, as shown in FIGURE 3 are provided, which runs adjacent the upper portion of the ducting for handling the primary carrier stream while a lower slot 91 is provided adjacent the underside of the ducting therefor. As noted in FIGURE 3, part 86 is also provided with an exterior slot 92 which is formed between the interior slots 90 and 91 and terminates to one side of the main carrier stream ducting. This same principle or characteristic is carried throughout the construction of the body 11 such as by providing additional lightening holes or reduction in mass such as may be represented by chambers 60, 93 and 94. Advantage is taken of these lightening chambers as in the instance of chamber 60 which serves as an inner communicating passageway between the venting duct 58 and 61 for venting the container 16.

The operation of the eductor illustrated in the drawings is suitable for use by a bather in connection with showering and may be employed as follows: The inlet tube 12 is screwed onto the receiving end of the body 11 within the body portion 25 which sealingly secures the vacuum breaker in position; the container 16 is filled with a concentrated liquid soap solution and is screwed into the threaded receptacle provided on portion 53 of the tube against the annular shoulder 59 and the water to be supplied via tube 12 is turned on. A stream of water will issue from the end of the nozzle 14. The handle 21 of the control means 17 is manually actuated to its on position so that passageway 81 communicates the ducting segments of duct 50 to provide a continuous passageway to interconnect the interior of the container with the expansion chamber 41. When the valve is in its ofi position, there is insufficient suction or drawing power on the secondary duct 50 of the eductor to draw up the soap solution. However, when the control means is actuated to its on position, suction is applied to the secondary duct 50 and the soap solution is drawn up through the duct 50 and through the small orifice provided in the restrictor 51 into the main water stream passing through the expansion chamber 41. The main carrier stream passes through the expansion chamber 41 from the throat 40 to the intermediate chamber 42 at such a high rate of velocity that an air seal is created around the body of the carrier stream within the chamber 41. The low pressure area created within the expansion chamber draws the liquid soap from the duct 50 where it mixes with the water of the main stream and is carried out of the nozzle. However, as the stream comes out of the bell-shaped chamber 43 into the nozzle 14, air may be introduced to the carrier stream which is mixed with the water-soap mixture under the influence of the screen 46, causing the mixture to foam and froth, with the result that a foamy, soapy stream is projected out of the nozzle 14 against the bather. As long as the valve means 17 is in the on position, soapy water will be aspirated and the froth will be produced. However, when the control means 17 is actuated to its off position, the supply of liquid soap ceases immediately so that only a stream of aerated rinse water issues from the nozzle 14. The vacuum breaker included in the chamber 28 acts to prevent drawback of any liquid soap residue in the secondary duct through the throat 40 to the main.

As soon as the bather has been thoroughly wet with the soapy foam, which because of its frothy character tends to cling to the skin surface it strikes, the bathers skin is then rinsed with the aerated clear water stream from the nozzle 14 but without suction on the liquid soap solution. The apparatus of the present invention permits a bather to be showered in a manner of minutes and in convenient for home use with any one of a number of synthetic liquid soap solutions now on the market. The device is rugged, has no moving parts other than the control valve and is inexpensive to manufacture.

The device gives the user suflicient soap and suds even under cold or hard water conditions and experience has found that only two gallons per minute of water is consumed during the average shower. The shower head is also kept free from lime deposits and clogged shower apertures and ports and soap is not wasted.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall Within the true spirit and scope of this invention.

1 claim:

1. In an eductor for drawing a second liquid into a carrier stream of a first liquid, the combination which comprises:

means coupling said stream to a first substantially cylindrical chamber; an elongated inlet throat chamber of constant diameter for receiving the liquid carrier stream from said first chamber, the diameter of said inlet throat being substantially smaller than the diameter of said first chamber; an expansion chamber of greater diameter and length than said throat chamber and coaxially arranged therewith to receive the carrier stream; a secondary duct opening into the side of said expansion chamber on one end and communicating with a supply of the second liquid on its opposite end;

control means interposed in said secondary duct having a first position and a second position whereby in said first position, the second liquid is conducted via said secondary duct to said expansion chamber and when in said second position, the supply of the second fluid is interrupted at which time said expansion chamber is vented to atmosphere;

said control means including a rotatable valve having a passage extending therethrough adapted to communicate between in-line duct segments of said secondary duct when said control means is in its first position and an elongated slot formed in said valve transverse to said valve passage adapted to communicate between said secondary duct and atmosphere to eifectively vent said expansion chamber; and vacuum breaker means within said first chamber for venting said first chamber to atmosphere.

2. The invention as defined in claim 1 including:

a metering jet disposed in said secondary duct between said expansion chamber and said control valve; and

means located in close proximity to said expansion chamber against which said metering jet seats so as to prevent said jet from entering into said expansion chamber.

3. The invention as defined in claim 1 including:

a nozzle movably attached to the eductor for discharging the carrier stream; and

a bell shaped conduit disposed between said first choke conduit and said nozzle adapted to substantially reduce back pressure when the nozzle is moved from one position to another.

4. The invention as defined in claim 1 including:

a container for holding a supply of the first liquid and being detachably secured to the eductor so that said secondary duct communicates with the first liquid supply; and

means for venting the bottom of said container to atmosphere so that the supply of the first liquid is reduced only by withdrawing the first liquid through said secondary duct in response to suction developed in said expansion chamber.

5. The invention as defined in claim 1, wherein said first chamber is coaxial with said inlet throat chamber and said vacuum breaker means is coaxially disposed in said chamber.

6. The invention as recited in claim 1, further comprising an 'apertured restrictor slidably disposed within said secondary duct.

7. In an eductor for drawing a first liquid into a carrier stream of another liquid, the combination which comprises:

a restricted throat through which the carrier stream is introduced;

a cylindrical expansion chamber of greater cross-section than said throat extending in the direction of the axis of said throat with said throat opening into an end of said expansion chamber abrubtly;

a first choke conduit of smaller cross-section than said expansion chamber disposed on the outward side thereof;

a secondary duct for the first liquid opening into the side of said expansion chamber near the end thereof and communicating with said throat;

control valve means including an elongated tapered stem rotatably mounted on the eductor and projecting through said secondary duct to interfere with the flow of the first liquid therethrough;

said valve stem having a passage extending therethrough adapted to interconnect with said secondary duct to conduct the passage of the first liquid therethrough;

said valve stem further having a slot formed in its outer surface adapted to communicate with said secondary duct to conduct the flow of air therethrough;

the eductor having a cavity formed therein for receiving the projecting end of said valve stem;

a washer loosely fitted in said cavity about the projecting end of said stem;

a cap having apertures formed therein communicating said cavity exteriorally of the eductor; and

said control valve means being manually rotatable between a position whereby said stem passage permits the first liquid to merge with the carrier stream and a position whereby said stem slot vents said expansion chamber to atmosphere via said eductor cavity and said cap apertures.

8. In an eductor for drawing a first liquid into a carrier stream of another liquid, the combination which comprises:

an elongated restricted throat through which the carrier stream is introduced;

an elongated cylindrical expansion chamber for receiving the carrier stream and being of greater crosssection and length than said throat and extending in the direction of the axis of said throat with said throat opening into an end of said expansion chamber abruptly .whereby substantial suction is developed therein;

a first choke conduit of smaller cross-section than said expansion chamber disposed on the outward side thereof;

a secondary duct for the first liquid opening into the side of said expansion chamber near the end thereof and communicating with said throat;

control valve means rotatably interposed in said secondary duct and having means for selectively and alternately communicating said expansion chamber with the first liquid to draw the liquid into merger with the carrier stream and communicating said expansion chamber to atmosphere to expel the suction developed in said expansion chamber; and

an apertured restrictor slidably disposed within said secondary duct between said valve means and said expansion chamber for metering the first liquid therethrough in response to suction developed in said expansion chamber;

said control valve means including an elongated tapered stem having a pre-determined surface area residing in said secondary duct;

said stem being formed with a passage extending there through in said surface area for communicating the interposed halves of said secondary duct to pass the first liquid therethrough and being formed with a slot about the periphery of said stem surface area along an axis normal to the axis of said passage and spaced apart therefrom to vent said expansion chamber to atmosphere when said slot is positioned in alignment with said secondary duct.

9. In an eductor for drawing a second liquid into a carrier stream of a first liquid, the combination which comprises:

a first chamber; a throat of smaller cross-section and coaxial with said first chamber opening into the end of said chamber;

an unvented expansion chamber of greater diameter and longer length than said throat extending in the direction of the axis of said throat with said throat opening into an end of said expansion chamber abruptly;

a secondary duct opening into the side of said expansion chamber at its end joining with said throat and communicating with a supply of the second liquid on its opposite end; and

control valve means interposed in said secondary duct having a first position and a second position whereby in said first position, the second liquid is conducted via said secondary duct to said expansion chamber and when in said second condition or position, said supply of the second fluid is interrupted and said expansion chamber is vented to atmosphere; the eductor including a body of plastic composition having a pair of mating sections separable along the central vertical plane of said body, each section of said pair having a tongue and groove arrangement whereby said sections may be indexed and joined together to constitute a unitary body, and a plurality of formed slots and chambers in said body arranged so as to substantially provide constant wall thickness and distribution of mass throughout said body.

References Cited UNITED STATES PATENTS 3,106,345 10/1963 Wukowitz 239-318 1,769,428 7/1930 Gatchet 239-318 2,571,871 10/1951 Hayes 239-318 2,571,891 10/1951 'Kassan et al. 134-57 2,646,063 7/ 1953 Hayes 1.37-218 2,788,245 4/1957 Gilmour 239-318 3,071,081 1/ 1963 Mullick 239-318 3,186,643 6/ 1965 George et a1 239-318 3,207,445 9/1965 Court et al. 239-318 3,231,200 l/1966 Heald 239-318 EVERETT W. KIRBY, Primary Examiner.

US. Cl. X.R. 

1. IN AN EDUCTOR FOR DRAWING A SECOND LIQUID INTO A CARRIER STREAM OF A FIRST LIQUID, THE COMBINATION WHICH COMPRISES: MEANS COUPLING SAID STREAM TO A FIRST SUBSTANTIALLY CYLINDRICAL CHAMBER; AN ELONGATED INLET THROAT CHAMBER OF CONSTANT DIAMETER FOR RECEIVING THE LIQUID CARRIER STREAM FROM SAID FIRST CHAMBER, THE DIAMETER OF SAID INLET THROAT BEING SUBSTANTIALLY SMALLER THAN THE DIAMETER OF SAID FIRST CHAMBER; AN EXPANSION CHAMBER OF GREATER DIAMETER AND LENGTH THAN SAID THROAT CHAMBER AND COAXIALLY ARRANGED THEREWITH TO RECEIVE THE CARRIER STREAM; A SECONDARY DUCT OPENING INTO THE SIDE OF SAID EXPANSION CHAMBER ON ONE END AND COMMUNICATING WITH A SUPPLY OF THE SECOND LIQUID ON ITS OPPOSITE END; CONTROL MEANS INTERPOSED IN SAID SECONDARY DUCT HAVING A FIRST POSITION AND A SECOND POSITION WHEREBY IN SAID FIRST POSITION, THE SECOND LIQUID IS CONDUCTED VIA SAID SECONDARY DUCT TO SAID EXPANSION CHAMBER AND WHEN IN SAID SECOND POSITION, THE SUPPLY OF THE SECOND FLUID IS INTERRUPTED AT WHICH TIME SAID EXPANSION CHAMBER IS VENTED TO ATMOSPHERE; SAID CONTROL MEANS INCLUDING A ROTATABLE VALVE HAVING A PASSAGE EXTENDING THERETHROUGH ADAPTED TO COMMUNICATE BETWEEN IN-LINE DUCT SEGMENTS OF SAID SECONDARY DUCT WHEN SAID CONTROL MEANS IS IN ITS FIRST POSITION AND AN ELONGATED SLOT FORMED IN SAID VALVE TRANSVERSE TO SAID VALVE PASSAGE ADAPTED TO COMMUNICATE BETWEEN SAID SECONDARY DUCT AND ATMOSPHERE TO EFFECTIVELY VENT SAID EXPANSION CHAMBER; AND VACUUM BREAKER MEANS WITHIN SAID FIRST CHAMBER FOR VENTING SAID FIRST CHAMBER TO ATMOSPHERE. 